<template>
  <div id="app">
    <div class="container">
      <!-- 顶部框模块 -->
      <div class="form-group">
        <div class="input-group">
          <h4>品牌管理</h4>
        </div>
      </div>

      <!-- 数据表格 -->
      <table class="table table-bordered table-hover mt-2">
        <thead>
          <tr>
            <th>编号</th>
            <th>资产名称</th>
            <th>价格</th>
            <th>创建时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <tbody>
          <tr v-for="obj in list" :key="obj.id">
            <td>{{ obj.id }}</td>
            <td>{{ obj.name }}</td>
            <!-- 如果价格超过100，就有red这个类 -->
            <td :class="{ red: obj.price >= 100 }">{{ obj.price }}</td>
            <td>{{ obj.time | formatTime }}</td>
            <td><a @click.prevent="delFn(obj.id)" href="#">删除</a></td>
          </tr>
          <tr v-show="this.list.length !== 0" style="background-color: #eee">
            <td>统计:</td>
            <td colspan="2">总价钱为:{{ allPrice }}</td>
            <td colspan="2">平均价:{{ averaPrice }}</td>
          </tr>
        </tbody>

        <tfoot v-show="this.list.length === 0">
          <tr>
            <td colspan="5" style="text-align: center">暂无数据</td>
          </tr>
        </tfoot>
      </table>

      <!-- 添加资产 -->
      <form class="form-inline">
        <div class="form-group">
          <div class="input-group">
            <!-- 资产名称 -->
            <input
              v-model.trim="name"
              type="text"
              class="form-control"
              placeholder="资产名称"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <div class="form-group">
          <div class="input-group">
            <!-- 资产价格 -->
            <input
              v-model.number="price"
              type="text"
              class="form-control"
              placeholder="价格"
            />
          </div>
        </div>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <!-- 阻止表单提交 -->
        <button @click.prevent="addFn" class="btn btn-primary">添加资产</button>
      </form>
    </div>
  </div>
</template>

<script>
import moment from "moment";

export default {
  //通过侦听器，本地存储，监听数据变化，
  watch: {
    list: {
      deep: true,
      handler() {
        //本地存储
        localStorage.setItem("list", JSON.stringify(this.list));
      },
    },
  },
  //通过计算属性，计算出总价和平均价
  computed: {
    allPrice() {
      //求和 reduce
      return this.list.reduce((sum, item) => (sum += item.price), 0).toFixed(2);
    },
    averaPrice() {
      return (this.allPrice / this.list.length).toFixed(2);
    },
  },
  //定义局部过滤器处理时间
  filters: {
    formatTime(time) {
      //传入的time就是要处理的时间数据
      return moment(time).format("YYYY-MM-DD  HH:mm:ss");
    },
  },
  methods: {
    //添加数据
    addFn() {
      //判断输入的内容
      if (this.name.length === 0 || this.price === 0)
        return alert("内容输入不规范");
      //新增就是操作数据，给数组添加新元素
      this.list.unshift({
        id: +new Date(),
        name: this.name,
        price: this.price,
        time: new Date(),
      });
      //新增完之后清空表单项
      this.name = "";
      this.price = "";
    },
    //删除数据
    delFn(id) {
      console.log(id);
      //findIndex做法
      // let index = this.list.findIndex((item) => item.id === id);
      // this.list.splice(index, 1);

      //简便做法，filter筛选数组，将和当前点击的数据的id相同的那个数据对象帅选出去，留下不一样的
      this.list = this.list.filter((item) => item.id !== id);
    },
  },
  data() {
    return {
      name: "", // 名称
      price: 0, // 价格
      //   list: [
      //     { id: 100, name: "外套", price: 199, time: new Date("2010-08-12") },
      //     { id: 101, name: "裤子", price: 34, time: new Date("2013-09-01") },
      //     { id: 102, name: "鞋", price: 25.4, time: new Date("2018-11-22") },
      //     { id: 103, name: "头发", price: 19900, time: new Date("2020-12-12") },
      //   ],
      list: JSON.parse(localStorage.getItem("list")) || [],
    };
  },
};
</script>

<style >
.red {
  color: red;
}
</style>